Julianne Hough's endometriosis "episodes" freaked her now-fiance out at the beginning of their relationship, because he couldn't understand why his girlfriend was doubled up in pain.

The Rock of Ages star, a former Dancing With the Stars regular-turned-judge, was diagnosed with the painful cramping condition in 2008 and is now a spokesperson for the Get in the Know About Me in EndoMEtriosis campaign, but she admits she wasn't always so open about the disorder.

Hough, who previously dated singer Chuck Wicks and TV personality Ryan Seacrest, tells Entertainment Tonight, "My fiance, at the beginning of our relationship, was like, 'What’s going on?' when I would have - I call them episodes - where I would have really bad pain and I'd be curled over.

"He’d be like, 'Are you ok?'. And now that I’m able to talk openly with him, he’s so supportive and gets it. And he’s not freaked out any more."

Julianne reveals she was diagnosed while she was dancing on TV: "When I was on Dancing With the Stars in 2008, I had really, really bad pain to the point where I had to actually leave the show. I was so scared,” she recalls. "I went to the hospital and everything. Fortunately, I had a great doctor who was able to diagnose me with endometriosis and it was such a relief because it was like, ‘Oh, I actually have a name to this pain'.

"It was comforting knowing that it wasn’t just something I had to deal with."

She is now committed to helping other sufferers, like actress Lena Dunham, who has also spoken out about her battle with the disorder.

"I just want people to feel supported and women to know they’re not alone in this," Julianne says. "I know I’m a tough cookie so I just want everybody else to know too. You don’t necessarily have to go through debilitating pain and just act like nothing’s wrong if you are having these symptoms.

"I'm not gonna lie, I definitely still have to stop certain things and take a few minutes if there are sharp pains... but I think because I have been open about it and I talk about it, people get it and it doesn’t feel like I have to hide it or that I have to bear through it. It’s like, ‘Hey, can you give me just a minute?’ And they’re like, ‘Yeah, absolutely'."